America’s rangelands represent almost half of all land mass in the West and are progressively threatened with drought, invasive species and wildfire. Climate change impacts the livelihoods of ranching communities and wildlife, both of which are integral to rangeland health. In response, land managers must balance ecosystem functioning with community livelihoods to prioritize prevention and mitigation. In the High Divide region of the West, state and federal agencies use vulnerability assessments to inform and guide conservation and adaptation plans on rangelands. The US Department of Agricultural and US Department of the Interior require agencies to address future impacts of climate change on both ecological systems and human communities that rely on them. Despite this, most existing vulnerability assessments focus on ecological vulnerabilities. This analysis aims to spatially visualize future climate hazards, social variables and estimates of uncertainty in the form of a social-ecological vulnerability map. Given the value of vulnerability assessments and agency management responsibilities map can guide priorities and allocation of resources for climate adaptation that protects both community and ecosystem health.
Perhaps once considered dry, unproductive and unremarkable landscapes, America’s rangelands are increasingly recognized as invaluable cultural and ecological systems as they become progressively threatened by climate change. Water scarcity and wildfire across the western United States is expected to increase in severity and frequency due to climate change (Schoennagel et al., 2017). Climate change impacts the livelihoods of ranching communities and wildlife, both of which are integral to rangeland health. The economies of rural rangeland communities rely on agriculture and recreation, and the semi-arid landscapes are home to dynamic agroecological systems. With careful stewardship, rangelands maintain soils, watersheds and carbon storage, but poor management can degrade wildlife habitat and destroy biodiversity (McNeeley et al. 2017). Representing almost half of all land mass in the West, these rangelands are mostly under federal management (Gorte et al. 2012). The USDA and US DOI require BLM and FS agencies to consider potential climate change impacts on both ecological systems and the human communities that depend on them (Fischer et al. 2013; Salazar 2009), yet no known assessments of US rangelands measure social-ecological vulnerability. Most assessments focus on ecological vulnerabilities, though human and natural system vulnerabilities are inextricably linked (Fischer and Frazier 2018).
Vulnerability assessments are valuable tools for federal, state and local agencies and managers to use to prioritize management action and develop adaptation responses to climate impacts (Glick, Stein, and Edelson 2011). Mapping social-ecological vulnerability in particular can provide visual aid to prioritize areas particularly vulnerable to climate impacts and in need of increased policy attention. While it is a dynamic measurement, vulnerability is generally defined as a function of exposure, sensitivity and adaptive capacity (Adger 2006). In the context of climate change, exposure describes how likely a species or system will experience change, sensitivity describes the likelihood and magnitude of how a species or system will be affected by a change, and adaptive capacity is the ability of a species or ecosystem to cope with climate impacts (Glick, Stein, and Edelson 2011). However, a consistent definition and framework of social-ecological vulnerability across this burgeoning field is still developing.
A survey of all US Department of the Interior vulnerability assessments revealed that few studies assessed wildfire risk or snowpack, both critical for Western landscapes (Thompson, Staudinger, and Carter 2015). The economic and cultural foundation of thousands of rural communities in the West are land-based, relying on ecosystem services provided by public land (McNeeley et al. 2017). Furthermore, adaptive capacity was the least frequently assessed component of vulnerability (Thompson, Staudinger, and Carter 2015). Adaptive capacity is a critical element of vulnerability in the West because rangeland managers often are limited in financial and infrastructural resources and are isolated from urban centers and governing agencies (Briske et al. 2015).
Rural communities whose livelihoods rely on drought- and wildfire-sensitive lands are vulnerable not only because of the environmental effects of climate change, but also due to their beliefs and perceptions about climate change. An assessment of vulnerability of rangeland systems can generate climate adaptation strategies and focus resources to improve adaptive capacity in this region. Adaptive capacity has never been measured using climate beliefs, but beliefs impact peoples’ ability to adapt (Arbuckle, Morton, and Hobbs (2013)]. Beliefs and perceptions affect adaptive capacity because personal perceptions of risks determine adaptation (Adger et al. 2012). For example, in studies of heatwaves affecting cities in the UK, US and Canada, the vulnerability of the elderly population intensified for those who did not perceive any risk to themselves, because their inflated perception of security diminished their adaptive capacity (Sheridan 2007; Wolf, Adger, and Lorenzoni 2010). Policy-makers should therefore consider beliefs and perceptions in order to measure climate change adaptation capacity (Briske et al. 2015), yet how beliefs and perceptions about climate change compound social-ecological vulnerability requires further investigation.
Rangeland resilience hinges on our understanding of the factors that promote and constrain adaptation, and our ability to work collaboratively with the community to develop programs that support adaptation. Policy can constrain or incentivize individual actions and should reduce vulnerability in susceptible human-environment systems. Most current policies consider environmental vulnerability, and not social implications. If policies were developed with those vulnerabilities in mind, we should be better equipped to adapt to a changing climate. In order to identify critical social and ecological vulnerability factors, we will interview ranchers and government agency land managers. We will synthesize and map USGS and other public data products that measure water, vegetation quantity and quality, fire risk and social factors. Working closely with the Climate Adaptation Science Centers, we will identify subject matter experts to review and provide feedback on prototypes. With this work we plan to evaluate rural and agricultural vulnerability to rangeland ecological drought in the West. By using the IPCC AR5, AR4, AR3, Extended frameworks we propose to use the findings for strategic planning and adaptation targeting.
The Climate Registry for the Assessment of Vulnerability (CRAVe) and the U.S. Climate Resilience Toolkit exist as open source community resources for managers and stakeholders to improve decision-making. The Resilience Toolkit contains an extensive set of tools and case studies that can be used to guide preventative actions and adaptation in different regions in the US. However, the Western US region is notably missing in the geographic coverage of the toolkit. This project will be complementary to additional USGS vulnerability ventures undertaken in the West. ‘Building Tribal Capacity to Assess Vulnerability to Climate Change’ addressed individual tribal social, cultural and economic needs and resulted in a vulnerability guide and solutions and improved access to relevant climate information. ‘Understanding Climate Change Vulnerability in the Pacific Northwest: A Comparison of Three Approaches’ analysis evaluates different assessment techniques for prioritizing climate change responses. These projects demonstrate the value of climate change vulnerability assessments to build capacity and awareness, as well as draw attention to knowledge gaps about such assessments and the complexity of climate change vulnerability. The deliverables of this project have the potential to inform program and policy design because they provide an understanding of social-ecological vulnerability to climate in communities where these assessments have not yet been conducted. With the growth in popularity of tools and maps, additional research is required to examine how effective such indices and assessments are at directing or informing policy or mitigation action.
Indicators will be selected through literature review and informational interviews with agencies and informed by ethnographic field work conducted in the region. For exposure, I will focus on wildfire and drought, using the USGS EROS Landsat Level 3 Burned Area Science Product (Hawbaker et al. 2017) and USGS WaterWatch, Probability of Streamflow Permanence (PROSPER) (Sando et al. 2018) or similar (Watson, Iwamura, and Butt 2013).
For sensitivity, I will use socioeconomic data from the American Community Survey and US Census Bureau. Data will include indicators for dependence on ranching, concentration of ranching employment and proportion of area used as grazeland.
For adaptive capacity, I will use traditional metrics such as formal education, social capital, physical ability and land-tenure security (Robinson et al. 2019), as well as climate belief data from the Yale Program on Climate Change Communication (YPCCC) (Howe et al. 2015). This data comprises the proposed working group of products and is subject to change as I develop the vulnerability index.
All datasets were projected to the World Geodetic System (WGS) 1984 global coordinate system. Vector/polygon data was converted to raster data at the same spatial resolution as gridded datasets. Ten arc minute vector grid squares were created in R across the entire study area, as the maximum spatial resolution of datasets used in the analyses. Spatial unit outputs should be mapped as counties and/or ecoregions.
The proposed deliverable of this project is an interactive online map of climate change vulnerability in the West. To reveal data which underlies the vulnerability index, the map will contain interactive layers of sensitivity, exposure and adaptive capacity. The county-level data associated with these layers, including climate beliefs, socio-economic factors, and biophysical characteristics will also be included.